Electric transmission line ground fault prevention methods using dual, high sensitivity monitoring

ABSTRACT

A method for preventing ground fault in a three-phase electric transmission line system caused by a line break, includes: providing a programmable relay protection system, including a plurality of relay devices on each line, programmed to include: preset parameter ranges of at least two electric operating conditions, at least one high sensitivity instantaneous undercurrent and at least one high sensitivity condition selected from line differential overcurrent and negative sequence overcurrent (and combinations thereof), the preset ranges being acceptable operating parameter ranges; monitoring; permitting closed circuit operation when all of the lines show that the two operating conditions are within the preset acceptable operating parameter ranges; tripping a circuit breaker on a broken line when that line shows that the two operating conditions are outside the preset parameter ranges; and shutting down power to the broken line before it otherwise causes a ground fault or other short circuit.

BACKGROUND OF INVENTION a. Field of Invention

High voltage (sometimes referred to as high tension) and other threephase electric transmission systems are prone to failing lines thatcause ground faults or other short circuits. Typically, such failuresresult from breaks in an individual line, connection breaks, objectintersection, aging, adverse weather, support structure failure, etc.For example, transmission lines that were built decades ago have aged tothe point where conductors (lines) separate from splices, or otherwisebreak and open with double jumpers and double dead end (DDE) towers.These double jumpers may slap against the steel towers or otherwiseground to cause fires and/or injury to structures, persons, animals andwildlife and flora. In the case of two major 2018 California fires, manyhomes and entire towns were destroyed by fire caused by ground faultsresulting from broken lines.

Historically, the industry has focused attention to preservation oftransmission lines, transformers, generators and substations bymonitoring systems for shorts and ground faults, reacting according tothe concept of best methods for preserving equipment and maintainingbest (least interrupted) services to the load (consumers). Thus, fordecades and presently, the industry utilizes preprogrammed relays thatmonitor operating conditions to identify shorts and to shut downelectricity on the shorted line and isolate to provide electricity tothe consumer. These relays react once a ground fault or other short hasoccurred. The present invention is directed to a very differentapproach—the use of methods, devices and systems that focus onidentifying a break in a line before a short or ground fault occurs,thereby preventing disasters that may result from such shorts and groundfaults. There are about 1.3 to 1.7 seconds between the time a linebreaks and the time a short occurs (i.e., the time it takes to touch aforeign conductor, such as ground, tower or building). The presentinvention is directed to unique approaches to see the break in real timewithin fractions of a second, even milliseconds, and to likewise shutdown the line (trip the breaker(s)) within fractions of a second and,hence, before any short occurs, avoid many possible disasters. This isachieved by micro-monitoring, looking at different parameters (operatingconditions) from those used in the prior art relays, and reacting nearlyinstantaneously.

b. Description of Related Art

The following patents are representative of the field pertaining to thepresent invention:

U.S. Pat. No. 6,518,767 to Roberts et al. describes a power line currentdifferential protection system. All three phase current values (I.sub.A,I.sub.B and I.sub.C) are obtained from both the local end and the remoteend of a power transmission line. The magnitude of the ratio of theremote current values to the local current values are calculated. Also,the angle difference between the local and the remote current values foreach phase are calculated. Comparison elements then compare the ratioand angle values against preselected values which establish a restrainregion in the current ratio plane. Current values which result in theratio being within the region do not result in a tripping signal for thecircuit breaker on the power transmission line, while current valueswhich result in a ratio outside of the region result in a tripping ofthe circuit breaker. Similar circuitry is used for negative sequencecurrent quantities, with the negative sequence preselected values beingset substantially lower to produce a more sensitive response to possiblefaults in the line.

U.S. Pat. No. 10,197,614 to Benmouyal et al. illustrates the errors thatare encountered when using both single-ended and double-endednormal-mode fault location calculations when a fault occurs in apole-open condition. The disclosure provides systems and methods foraccurately calculating the location of faults that occur duringpole-open conditions, including single-ended approaches and double-endedapproaches.

U.S. Pat. No. 10,340,684 to Sridharan et al. describes how a location ofa broken electrical conductor of an electric power delivery system maybe detected by monitoring a rate of change of phase voltage and/or arate of change of zero-sequence voltage at various points on theconductor. Intelligent electronic devices (IEDs) such as phasormeasurement units may be used to obtain measurements and calculatesynchrophasors. The synchrophasors may be used by a central controllerto determine which two continuous IEDs measure rates of change ofvoltages of opposite polarities, where the broken conductor is betweenthe two continuous IEDs. The synchrophasors may be used by a centralcontroller to determine which two continuous IEDs where one exhibits azero-sequence voltage magnitude that exceeds a predetermined thresholdfor a predetermined time, wherein the zero-sequence voltage magnitude ofthe other of the continuous IEDs does not exceed the predeterminedthreshold.

U.S. Pat. No. 10,823,777 to Dase et al. relates to detecting a brokenconductor in a power transmission line. In an embodiment, a processorreceives a signal indicating current on the transmission line. Theprocessor determines that a broken conductor is present on thetransmission line based at least in part on a magnitude of the currentbeing less than a line charging current of the transmission line and aphase angle of the current leading a respective phase voltage of thetransmission line. The processor effects a control operation based onthe determined broken conductor.

U.S. Pat. No. 10,955,455 to Thompson et al. pertains to detection of abroken conductor in an electric power system. In one embodiment, abroken conductor detector may be configured to be mounted to anelectrical conductor and may comprise a communication subsystemconfigured to transmit a signal configured to indicate that theconductor is broken. A sensor may determine an operating vector. Aprocessing subsystem may be configured to receive the operating vectorfrom the sensor and to identify when the operating vector is outside ofa range defined by a rest vector and a threshold value. In certainembodiments, the threshold may comprise a three-dimensional sphere. Theprocessing subsystem may determine that the conductor is broken based onthe operating vector remaining outside of the range for a period of timedetermined by the timer subsystem. A signal may be transmitted by thecommunication subsystem to indicate that the conductor is broken.

U.S. Pat. No. 11,211,788 to Wade et al. describes how systems andmethods may mitigate risk of fire caused by an electric power system. Inone embodiment, a system may include an intelligent electronic device(IED). The IED includes a communication subsystem to receive a signalfrom a sensor related to a condition of the electric conductor. Aprocessing subsystem in communication with the communication subsystemmay operate in at least two modes comprising a high security mode and afire prevention mode. In the fire prevention mode, the IED may interrupta flow of electric current based on the signal from the at least onesensor associated with the electric conductor. In the high securitymode, the system may interrupt a flow of electric current based on thesignal from the at least one sensor associated with the electricconductor and based on a second condition relating to the electricconductor.

U.S. Publication No. 20190317143 to Gangadhar et al. relates todetecting a broken conductor in a power transmission line. In anembodiment, a processor receives a signal indicating current on thetransmission line. The processor determines that a broken conductor ispresent on the transmission line based at least in part on a magnitudeof the current being less than a line charging current of thetransmission line and a phase angle of the current leading a respectivephase voltage of the transmission line. The processor effects a controloperation based on the determined broken conductor.

U.S. Publication No. 20190324074 to Thompson et al. pertains todetection of a broken conductor in an electric power system. In oneembodiment, a broken conductor detector may be configured to be mountedto an electrical conductor and may comprise a communication subsystemconfigured to transmit a signal configured to indicate that theconductor is broken. A sensor may determine an operating vector. Aprocessing subsystem may be configured to receive the operating vectorfrom the sensor and to identify when the operating vector is outside ofa range defined by a rest vector and a threshold value. In certainembodiments, the threshold may comprise a three-dimensional sphere. Theprocessing subsystem may determine that the conductor is broken based onthe operating vector remaining outside of the range for a period of timedetermined by the timer subsystem. A signal may be transmitted by thecommunication subsystem to indicate that the conductor is broken.

U.S. Publication No. 20210048486 to Bell et al. describes systems fordetermining a broken conductor condition in a multiple-phase electricpower delivery system. It has been observed that broken conductors posea safety concern when occurring in the presence of people or vulnerableenvironmental conditions. Broken conductor conditions disclosed hereinmay be used to detect and trip the phase with the broken conductor, thusreducing or even eliminating the safety risk. Further, a distance to theopening may be determined.

U.S. Publication No. 20210091559 to Mobley et al. pertains to detectionof a broken conductor in an electric power system. In one embodiment, abroken conductor detector may be configured to be mounted to anelectrical conductor and may comprise a communication subsystemconfigured to transmit a signal configured to indicate that theconductor is broken. A sensor may determine a plurality of vectors. Aprocessing subsystem may be configured to receive the plurality ofvectors from the sensor and to identify when the vector is outside of arange defined by a threshold value. The processing subsystem maydetermine that the conductor is falling based on the plurality ofvectors remaining outside of the threshold for a period of timedetermined by the timer subsystem. A signal may be transmitted by thecommunication subsystem to indicate that the conductor is falling.

U.S. Publication No. 20210265834 to Wade et al. describes how systemsand methods may mitigate risk of fire caused by an electric powersystem. In one embodiment, a system may include an intelligentelectronic device (IED). The IED includes a communication subsystem toreceive a signal from a sensor related to a condition of the electricconductor. A processing subsystem in communication with thecommunication subsystem may operate in at least two modes comprising ahigh security mode and a fire prevention mode. In the fire preventionmode, the IED may interrupt a flow of electric current based on thesignal from the at least one sensor associated with the electricconductor. In the high security mode, the system may interrupt a flow ofelectric current based on the signal from the at least one sensorassociated with the electric conductor and based on a second conditionrelating to the electric conductor.

Published article 2016 IEEE “Catching Falling Conductors inMidair—Detecting and Tripping Broken Distribution Circuit Conductors atProtection Speeds” by William O'Brien, Eric Udren, Kamal Garg, DennisHaes, and Bala Sridharan describes how when an overhead electric powerdistribution circuit conductor breaks—for example, when a car strikes apole or a splice or clamp fails—the energized conductor falls to ground.The resulting high-impedance ground fault may be difficult or impossibleto detect by relays located in the substation. In any case, no groundfault protection relay can operate until well after the time the faulthas occurred—after the falling energized conductor has hit the groundand created a hazardous situation. For decades, utilities and equipmentmanufacturers have worked to develop methods for tripping thesehazardous ground faults as quickly as possible. This paper describes anew falling conductor detection scheme that trips the affected circuitsection in the narrow time window between the moment of the break andthe time the conductor hits the ground. The affected circuit section isde-energized while the conductor is still falling, eliminating the riskof an arcing ground fault or energized circuits on the ground.

Published article 2019 Schweitzer Engineering Laboratories, Inc.“Detecting and Locating Broken Conductor Faults on High-Voltage Lines toPrevent Autoreclosing Onto Permanent Faults” by Kanchanrao Dase, SajalHarmukh, and Arunabha Chatterjee describes how broken-conductordetection is challenging because the conductor may remain suspendedwithout causing any fault current. Even if the conductor falls to theground, the fault current might remain low, depending on the faultresistance. For low-resistance faults, a relay can detect faults andtrip the line breakers. However, because the relay cannot determinewhether the fault is permanent, it may attempt to reclose, causingfurther stress to the power system. This paper describes a new algorithmthat uses only single-ended measurements to reliably detect brokenconductors and estimate their location by using the charging current ofthe line. The phase angle of this current leads the voltage by about<90°, and the magnitude is a function of line length. This method issuitable for power lines that have measurable charging current, and itdetects broken conductors successfully if the relay can measure thecharging current while the conductor is falling in midair.Broken-conductor detection can be used to trip the breakers before theconductor touches the ground and creates a shunt fault. Thus, thealgorithm can prevent such faults and block any attempt to reclose theline. Detecting broken conductors and their location informationprovided by the algorithm can help in quickly resolving broken-conductorfaults. This paper presents three field events from 57.1 kV and 220 kVlines and results from Electromagnetic Transients Program (EMTP)simulations that validate the algorithm.

U.S. Pat. No. 9,753,096 to Kim and related U.S. Pat. No. 8,866,626 toKim both describe a method, system and computer software for detectingan incipient failure of a generator in a power system including thesteps of ascertaining one or more generator reference parameter of thegenerator for use as a baseline reference; measuring one or moreoperating parameter values of the generator; using the one or moreoperating parameter values to solve for an estimated present value ofthe one or more of the generator's current performance parameters usingparticle swarm optimization technique; and determining whether theestimated present values of the one or more of the generator's currentperformance parameters are outside of an acceptable limit.

U.S. Pat. No. 7,345,456 to Gibbs et al. describes a stabilizer andsynchronous electric power generator system using same that providesboth power system damping and excitation limiter functionality. Thestabilizer includes a processing unit and a memory storing routinesexecutable by the processing unit. The routines are adapted to receive avoltage signal indicative of a voltage and a current signal indicativeof a current output by the generator system, generate, utilizing thevoltage and current signals, a power system stabilizer signal fordamping oscillations and one or more excitation limiter function signalsfor controlling excitation level. The routines are also adapted togenerate a feedback signal for the generator system by combining thepower system stabilizer signal and one or more of the one or moreexcitation limiter function signals.

U.S. Pat. No. 5,761,073 to Dickson describes a programmableautosynchronizer for use with a system having generator and bus voltagesand having a breaker circuit for connecting the generator and busvoltages to each other. The autosynchronizer synchronizes the frequencyand phase of the generator and bus AC voltages by controlling thegenerator voltage. A microprocessor compares the frequencies ofgenerator and bus voltage signals, the microprocessor generating aproportional difference signal having a parameter representative of aproportional difference in frequency between the generator and busvoltage signals. The proportional correction range extends within thesynchronization range. The microprocessor permits a sync signal when thefrequency difference of the frequencies of the generator and bus voltagesignals is within the synchronization frequency range. A first outputcircuit responsive to the proportional difference signal provides acorrection signal to the generator for varying the frequency of thegenerator. A second output circuit responsive to the sync signalprovides a breaker close signal to the breaker circuit for closing thebreaker thereby enabling connection of the generator and bus voltages. Afrequency correction dead band within the frequency range and a targetslip band within the dead band define a zone of limited proportionalcorrection to nudge the generator into synchronization and prevent ahung scope.

U.S. Pat. No. 5,751,532 to Kanuchok, et al. describes a relay formonitoring an electrical system to protect the electrical system from anovercurrent condition as a time dependent function of an electricalcurrent level in the electrical system. The relay includes a memorywhich stores a current level count and a current level detector coupledto the electrical system which detects the electrical current level inthe electrical system over time. A microprocessor responds to thecurrent level detector by varying the current level count in the memoryas a function of the electrical current level over time. Themicroprocessor also detects an occurrence of the electrical currentlevel falling below a minimum current level. A timer responds to themicroprocessor by measuring a period of time during which the electricalcurrent level is less than the minimum current level. The microprocessorresponds to the timer by varying the current level count in the memoryas a function of the measured period of time during which the electricalcurrent level is below the minimum current level. A method of monitoringan electrical system to protect the electrical system from anovercurrent condition as a time dependent function of an electricalcurrent level in the electrical system is also disclosed. Otherapparatus and methods are also disclosed.

U.S. Pat. No. 5,640,060 to Dickson describes an autosynchronizer for usewith a system having generator and bus voltages and having a breakercircuit for connecting the generator and bus voltages to each other. Theautosynchronizer synchronizes the frequency and phase of the generatorand bus AC voltages by controlling the generator voltage. Amicroprocessor compares the frequencies of generator and bus voltagesignals, the microprocessor generating a proportional difference signalhaving a parameter representative of a proportional difference infrequency between the generator and bus voltage signals. Theproportional correction range extends within the synchronization range.The microprocessor permits a sync signal when the frequency differenceof the frequencies of the generator and bus voltage signals is withinthe synchronization frequency range. A first output circuit responsiveto the proportional difference signal provides a correction signal tothe generator for varying the frequency of the generator. A secondoutput circuit responsive to the sync signal provides a breaker closesignal to the breaker circuit for closing the breaker thereby enablingconnection of the generator and bus voltages. A frequency correctiondead band within the frequency range and a target slip band within thedead band define a zone of limited proportional correction to nudge thegenerator into synchronization and prevent a hung scope.

U.S. Pat. No. 5,309,312 to Wilkerson, et al. describes an apparatus forprotecting an electrical power system supplying electrical power to anelectrical load comprises a transformer for sensing an operatingcondition of the electrical power system and for producing an analogsignal representative of the operating condition, and a microcomputerfor periodically sampling the analog signal and for converting theanalog signal into a series of digital signals. The microcomputerincludes circuitry for deriving a digital value representative of asquare root of the series of digital signals and circuitry forprocessing the digital value over time to determine a processed valuewhich is a function of both the sensed operating condition and time. Acircuit breaker is responsive to the microcomputer for disconnecting thepower system from the load in the event that the processed value is notwithin preset limits. The microcomputer also generates a relay signalrepresentative of the status of the relay and the relay includes anoutput port responsive to the relay signal, for communicating the statusof the relay to a remote station.

U.S. Pat. No. 5,014,153 to Wilkerson describes an apparatus formonitoring phased currents in a first winding and a second winding of atransformer and for disconnecting the transformer from a power sourcesupplying the transformer when a difference between the magnitude of thecurrent in the first winding and the magnitude of the current in thesecond winding exceeds a predetermined amount to indicate a faultcondition is disclosed. The apparatus is used in combination withcircuitry for generating first and second current signals each having aphase and magnitude which is a function of the phase and magnitude ofthe phased currents in the first and second windings, respectively. Theapparatus includes a circuit for shifting the phase of the secondcurrent signal to match the phase of the first current signal, a circuitfor detecting a difference between the magnitude of the first currentsignal and the magnitude of the phase shifted second current signal, anda circuit for disconnecting the transformer from the power source whenthe detected difference exceeds the predetermined amount.

U.S. Pat. No. 4,788,619 to Ott et al. describes a protective relay foruse in an electrical power system having electrical conductors which areenergized with an AC voltage. The protective relay includes a circuitfor sensing the AC voltage to produce an AC output that has zerocrossings and a time period between zero crossings, a circuit forsupplying an electrical signal representing a preselected pickup valueof volts-per-Hertz for the relay, and a circuit responsive to the ACoutput and to the electrical signal for generating an electrical levelas a function of both the time period and the pickup value and forproducing an output signal for the relay when the AC output exceeds theelectrical level. In this way, the output signal is produced when avolts-per-Hertz value of the AC voltage exceeds the preselected pickupvalue of volts-per-Hertz for the relay. Other protective relay apparatusand methods are also disclosed.

U.S. Pat. No. 4,757,416 to Wilkerson describes a protective apparatusfor use in an A.C. electrical power system with a circuit breaker forconnecting and disconnecting first and second electrical conductors thatare electrically energized, the conductors normally having a negligiblephase difference of electrical energization when the circuit breaker isclosed, and the circuit breaker having auxiliary contacts defining thestate of the circuit breaker as open or closed. The protective apparatusincludes a circuit responsive to the auxiliary contacts for producing afirst signal representative of the state of the breaker as open orclosed and another circuit connected to the circuit for producing thefirst signal and operable when the breaker is closed for generating asecond signal when the phase difference of electrical energization ofthe first and second electrical conductors exceeds a predeterminedvalue. A further circuit provides an indication of malfunction of thecircuit breaker when the second signal occurs. Phase window extendingapparatus for use in the protective apparatus, methods of operation andother protective apparatus are also disclosed.

Notwithstanding the prior art, the present invention is neither taughtnor rendered obvious thereby.

SUMMARY OF INVENTION

The present invention relates to a method for preventing ground fault orother short circuit in a three-phase electric transmission line systemhaving at least three lines (phases), caused by a break in a line. Themethod includes providing a programmable relay protection system,including a plurality of communicating relay devices on each line of theelectric transmission line system. These relay devices may be newlycreated or existing but are programmed differently from existingprotection relays. Thus, the present invention relay protection systemis programmed to include: a) preset parameter ranges of at least twohigh sensitivity electric operating conditions, one of which isinstantaneous undercurrent, and the other of which is selected from (i)line differential overcurrent, (ii) negative sequence overcurrent, and(iii) combinations thereof, the preset ranges being acceptable operatingparameter ranges; b) monitoring means to monitor each line at each ofthe plurality of relay devices for the at least one operating condition;c) permitting closed circuit operation when all of the lines show the atleast two operating conditions are within the preset acceptableoperating parameter ranges; d) a tripping mechanism to trip a circuitbreaker on a broken line when that line shows the at least one operatingcondition is outside the preset parameter ranges. The preferred conceptis to program the relays to sense the aforementioned conditiondeviations from the preset parameter ranges, that occur at both brokenends of a broken line, and shut down the power to the broken line, andto do these functions on an extremely rapid basis, preferably under 1.0second, and most preferably under 50 milliseconds. That is, to completethe monitoring, recognize the break's two change in these monitoredconditions sensed to be outside the operating ranges, communicate withbreaker(s), and shut down the power, all before the broken line touchesa tower, pole or ground.

In some preferred embodiments, the present invention method includessensing open conductor broken line within 0.5 second of the break, whenthe at least two operating conditions (one of which is instantaneousundercurrent, and the other of which is selected from (i) linedifferential overcurrent, (ii) negative sequence overcurrent, and (iii)combinations thereof) falls outside of the preset parameter ranges, andbefore the broken line touches a tower, pole or ground, and, when therelay protection system senses the open conductor broken line monitoredconditions on a broken line that is outside of the preset parameters,communicating to open the circuit breaker on the broken line to shutdown within another 0.5 seconds, thereby shutting down power to thebroken line before it otherwise causes a ground fault or other shortcircuit, i.e., before one or both ends at the break of a broken linetouches a tower, pole or ground.

In some preferred embodiments of the present invention method forpreventing ground fault or other short circuit in a three-phase electrictransmission line system, the plurality of relay devices on each line isprogrammed to monitor both upstream and downstream from each of theplurality of relay devices such that when a line is broken, themonitored conditions of both ends of the break is recognized andreported in the system to effect the shutting down power to the brokenline by tripping two circuit breakers, one being upstream from the breakand the other being downstream from the break.

In some preferred embodiments of the present invention method, theprogrammable relay protection system relay devices are programmed tomonitor highly sensitive line differential overcurrents to detectcurrent imbalance on line-charging capacitive current. In some preferredembodiments of the present invention method, the relay devices areprogrammed to be highly sensitive so as to monitor and measuredirectional overcurrent in the range of 0.01 to 1 amp. In some preferredembodiments of the present invention method, the relay devices areprogrammed to be highly sensitive so as to monitor and measure negativesequence overcurrent in the range of 0.01 to 1 amp. In some preferredembodiments of the present invention method, the relay devices areprogrammed to be highly sensitive so as to monitor and measureinstantaneous undercurrent in the range of 0.1 to 2 amps.

In some preferred embodiments of the present invention method, the relayprotection system includes sufficient software and hardware forrecognizing breakage capacitive current within 20 milliseconds when theat least one operating condition falls outside of the preset parameterranges, and communicating to open the circuit breaker on the broken linewithin another 20 milliseconds, thereby shutting down power to thebroken line before it otherwise causes a ground fault or other shortcircuit.

In some preferred embodiments of the present invention method, the relayprotection system includes a plurality of relay devices having phasorsfor monitoring all three phase voltages and currents and phase anglesimilarities and differences to detect capacitive current and deviationsfrom preset ranges thereof.

In some preferred embodiments, the present invention methods and devicesrely upon certain combinations of deviations from preset conditions to“call the alarm”, i. e., to signal trips to the breakers. This ensuresthat a single random deviation caused by a glitch does not unnecessarilyclose down a power line. AND gates are used to require condition A andcondition B to be simultaneously showing deviations to allow the “alarm”to occur. OR gates, likewise, only require a single AND gate feed totrigger the breaker trip.

Thus, in a first group of gate embodiments of the present invention,there are at least two AND gates and at least one OR gate for processingmonitored data readings and tripping breakers, including a first ANDgate that receives line differential overcurrent readings andinstantaneous undercurrent readings, and includes a second AND gate thatreceives negative overcurrent readings and instantaneous undercurrentreadings.

Other groups of gate embodiments may also be used. Thus, in anothergroup of gate embodiments, another AND gate or two may replace gates insome of the above-described gate groups or be added to them. Thus, theAND gates may include an AND gate that receives (a) undercurrentreadings and (b) negative sequence current readings and/or an AND gatethat receives (a) undercurrent readings and (b) negative sequencevoltage readings.

Additional features, advantages, and embodiments of the invention may beset forth or apparent from consideration of the following detaileddescription, drawings, and claims. Moreover, it is to be understood thatboth the foregoing summary of the invention and the following detaileddescription are exemplary and intended to provide further explanationwithout limiting the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate preferred embodiments of theinvention and together with the detail description serve to explain theprinciples of the invention. In the drawings:

FIG. 1 is a block diagram showing some of the features of a Prior Arthigh voltage electric transmission relay protection system;

FIG. 2 is a block diagram showing some of the features of a PresentInvention high voltage electric transmission relay protection systemthat relies upon micro monitoring of highly sensitive lineconditions—namely, one of which is instantaneous undercurrent, and theother of which is selected from (i) line differential overcurrent, (ii)negative sequence overcurrent, and (iii) combinations thereof;

FIG. 3 illustrates a diagram of a present invention protection systemusing two programmable relays located at opposing substations andmonitoring at least two of the aforesaid conditions on all three lines(also referred to as wires, wire conductors, conductor wires orconductors herein) at both substations;

FIGS. 4 and 5 show high voltage transmission lines before a break andafter a break (before shorting), respectively, with present inventionrelays (PIRs) at each substation;

FIGS. 6, 7 and 8 show various present invention AND gate/OR gatearrangements used to monitor conditions and initiate breaker tripping toprevent ground faults after a line break and before a line touches atower, pole or ground;

FIG. 9 shows another alternative present invention gate arrangement;

FIGS. 10 and 11 , respectively, illustrate Prior Art protection systemsand Present Invention protection systems analysis for an actual 500kilovolt, 1500 amp high voltage transmission line, and the phenomenalability of the present invention system to completely eliminatecollateral and catastrophic damage that is possible to occur with thePrior Art systems;

FIGS. 12 and 13 , respectively, illustrate Prior Art protection systemsand Present Invention protection systems analysis for an actual 115kilovolt, 100 amp high voltage transmission line, and the phenomenalability of the present invention system to completely eliminatecollateral and catastrophic damage that is possible to occur with thePrior Art systems.

DETAILED DESCRIPTION OF THE INVENTION

Electricity begins with production of power, i.e. the source, in theform of any electric-producing-facility, fossil fuel power plant,hydroelectric, wind farm, solar farm, hybrid, co-generation, etc. Whenelectricity is produced, it is next distributed and then consumed. Thefour major aspects are production, transmission, distribution andconsumption. Transmission usually begins with high voltage (sometimescalled high tension) lines transmitting from the source, through thelines, to the load. Distribution involves step-down substations withtransformers and other components to regulate electric flow. It is wellknown that resistance will cause huge drops in delivered electricity tothe load, and it is well known that the negative effect of resistancealong the lines (wires) can be significantly reduced by lowering thecurrent and increasing the voltage. As an example, a 110 volt line couldlose over 70% of its value before reaching a load, depending upon linematerial and distance, whereas high voltage lines operating at very highvoltages, such as 345 kilovolts, might lose only 0.5% of its value tothe load over many miles. Large amounts of power can only be transmittedover long distances by very high and extremely high voltage transmissionlines from a practical standpoint, otherwise resistive losses of energyare prohibitive.

For decades (at least 50 years), high voltage transmission systems havegrown into significant sizes that are interconnected into what is calleda grid, e.g. the North America grid. The grid is a mixture of differenttransmission voltages that is utilized because it is often used to shareproduction resources in one region, taking power from one region andsending it to another region. One significant disadvantage is that adowned line or lines, on one segment or region of a grid, may causeother operating segments or regions to overload and shut down. Hence,the domino theory (one falls down and others follow sequentially) hasapplied to grids around the world, causing hundreds of thousands or evenmillions of consumers to lose power for significant periods of time.

To countermand these happenstances, grid reconfigurations, newequipment, new software, added redundancies and other support featureshave been added to the grid. In addition, line monitoring for shortcircuits, including ground faults, and shutting down circuits inresponse, is an integral part of high voltage (“HV”) transmissionsystems, also known as high voltage transmission systems.

Thus, for decades, programmable relays have been used to identify andrespond to short circuits. The term “ground fault” as used herein, ismeant to reference a disruption caused by a live wire or other liveelectric component unintentionally contacting a conductor, such as aconductive structure, the ground, a body of water, etc. The term “brokenline” as used herein shall be taken broadly to include live wires, liveconnectors, live splices and splice components that have experienced abreak in the circuity with a short or fault that has or is about tooccur.

Referring now in detail to the drawings wherein like reference numeralsdesignate corresponding parts throughout the several views, variousembodiments of the present invention are shown.

The standard in the industry is to monitor the transmission system torecognize a ground fault and to react to it. The conventional steps ofthe PRIOR ART are shown in FIG. 1 , block 1 (Prior Art High VoltageElectric Transmission Relay Protection Systems) are:

(1) deploy programmable, communicating relays along transmission lines,block 3;

(2) program these relays to monitor macro changes in electric conditionsalong the lines to identify when a ground fault has occurred, block 5;

(3) communicate to the appropriate breaker to shut down the breakerafter the ground fault has occurred with possible collateral damage andpossible catastrophic damage, block 7;

(4) shift power as quickly as possible to by-pass (isolate) the brokenline to other transmission lines to minimize disruption, block 9 (thisoccurs with existing equipment and grid configurations as thetransmission system reconfigures);

(5) locate the broken line and repair/replace it, block 11, and;

(6) restore power to the previously broken line, block 13.

This prior art procedure seems to be used frequently, if notuniversally, but has the disadvantage of collateral damage, from minorproperty, livestock or flora and fauna damage, to significant collateraldamage-fires, destruction and the like, to catastrophic collateraldamage-loss life or many lives, destruction of valuable property, suchas in the millions or even hundreds of millions of dollars, and evendestruction of entire communities.

The present invention is directed to the elimination of all collateraland catastrophic damage caused by a short or ground fault. This isachieved by utilizing micro monitoring programming in the relays to notlook at ground faults, but to micro monitor small changes in capacitivecurrent and capacitive voltage that occurs after a line is broken andbefore it shorts or grounds (that is, before it touches a tower, pole,ground or other grounding object). “Micro” as used herein does not meanone millionth or other exact measurement, but rather is intended toconnote very small measurements on a relative basis. In this context,the present invention measurements are at least an order of magnitudesmaller than present commercial relays measurements that occur upon ashort or ground fault. For lower range high voltage systems, the presentinvention methods are monitoring conditions that are two or even threeorders of magnitude smaller. Further, in the present invention methods,timing is critical and the conditions measured are different andcritical. This unique approach enables breakers to be shut down (andhence cease electric flow) before any collateral damage could otherwiseoccur.

FIG. 2 shows the steps in the present invention high voltagetransmission relay protection system, block 21, and preferredembodiments include these steps:

(1) deploy programmable, communicating relays along transmission lines,preferably at or near the substations, block 23. Communications must bevery rapid, such as radio, and preferably optical fiber communications;

(2) program these relays to monitor micro changes in electricconditions, namely instantaneous undercurrent, and one other of theaforesaid operating conditions, namely, selected from the groupconsisting of a) line differential overcurrent; b) negative sequenceovercurrent and c) combinations thereof, along the lines to identifywhen a line break has occurred and to do so before the broken linecreates a fault, block 25, (before it touches a tower, pole or ground),e.g., within a half-second and preferably within a few milliseconds;

(3) rapidly communicate to the appropriate breakers to shut down thebreakers at both ends of the break before the ground fault has occurred,block 27 (again within a half-second and preferably within a fewmilliseconds) to avoid collateral damage or catastrophe, had the groundfault actually occurred;

(4) shift or by-pass (isolate) power as quickly as possible to minimizedisruption, block 29 (this occurs with existing equipment and gridconfigurations as the transmission system reconfigures);

(5) locate the broken line and repair/replace it, block 31, and;

(6) restore power to the previously broken line, block 33.

By the present methods and devices, it can now be seen that the speed inwhich the monitoring and corrective action takes place is a fraction ofa second or a second. Due to the present invention methods shut downbefore a fault occurs, no damage results and easier, safer and quickerbroken line repair is achieved.

FIG. 3 illustrates a diagram of a present invention protection systemusing two programmable relays located at opposing substations andmonitoring at least two selected conditions. In one embodiment, theseconditions are: a) instantaneous undercurrent, and b) line differentialovercurrent. In another embodiment, these conditions are: a)instantaneous undercurrent, and b) negative sequence overcurrent. Inanother embodiment, these conditions are: a) instantaneous undercurrent,in combination with b) line differential overcurrent, as well as c)instantaneous undercurrent, in combination with d) negative sequenceovercurrent. Another embodiment is a) instantaneous undercurrent, incombination with b) line differential overcurrent, as well as c)negative sequence overcurrent. Additional conditions could be added,such as may be described below in conjunction with the gates.

One of these two relays is shown in greater detail than the other, butboth are identical. In FIG. 3 , a structurally conventional relay device50 is shown with a present-day relay microprocessor with computersoftware, hardware, and firmware that processes the software foradjusting the input parameters of the electric conditions, voltages andcurrents, to determine when adverse conditions occur. A second,identical relay 94 is also shown. These two relays 50 and 94 areprogrammed differently from normal relays used in the industry, as theyare programmed to measure sensitive readings and not large readings,and, more specifically, are programmed to measure/monitor changes thatoccur before fault occurs. These “micro” changes relate to what occursat the broken ends of a line before either end touches anything to shortor ground. Such readings are bypassed, or ignored, by the prior artsystems programming, as breakers are not tripped in the prior artsystems until after the short or fault occurs. Here the aforementionedconditions are monitored and when they deviate from the presetacceptable operating ranges, the breakers are tripped. These relays sendtrip signals to the circuit breaker(s) within a second, and even within20 or so milliseconds to de-energize the line. In preferred embodiments,the present invention relays are programmed to monitor in bothdirections (upstream and downstream from current flow) and trip bothrelated breakers.

Table 1 lists the various components of the present invention protectionsystem shown in FIG. 3 , and the detailed relationship of each componentis set forth below Table 1:

TABLE 1 FIG. 3 Present Invention System Components (Drawing ReferenceNumber and Component)  50 Present Invention First Relay.  51 Three PhasePower Grid.  52 A phase transmission line conductor.  54 B phasetransmission line conductor.  56 C phase transmission line conductor. 58 A phase potential transformer.  60 B phase potential transformer. 62 C phase potential transformer.  64 A phase current transformer.  66B phase current transformer.  68 C phase current transformer.  70 Wireconnecting 58 to relay 50 for A phase voltage input. (VA)  72 Wireconnecting 60 to relay 50 for B phase voltage input. (VB)  74 Wireconnecting 62 to relay 50 for C phase voltage input. (VC)  76 Wireconnecting 64 to relay 50 for A phase current input. (IA)  78 Wireconnecting 66 to relay 50 for B phase current input. (IB)  80 Wireconnecting 68 to relay 50 for C phase current input. (IC)  82 Wireconnecting ground to relay 50 for ground potential for use in relay 50.(GND)  84 Wire connecting the trip signal from Relay 50 to CircuitBreaker 86.  86 Circuit Breaker associated with the downed conductordetection system connected to Relay 50.  88 Circuit Breaker associatedwith the transmission line at the other end of the line, associated withthe downed conductor detection system connected to Relay 94.  90Communications port to send and receive data communications.  92Communications port for testing Relay 50 and for making software changesand modifying relay settings.  94 Present Invention Second Relay.  96Communication Center between Relays 50 and 94. 100 First Substation. 200Second Substation (next downstream from First Substation).

The transmission lines of power grid 51 transport electric power to bedelivered to meet customer demand. At the power generation end, astep-up transformer substation transmits the power through thetransmission lines at very high voltages, and at the downstream end, astep-down transformer sends power through a distribution line at normalvoltages. In between the beginning and end of a power grid, numerousintermediate substations are positioned to distribute power to localusers. In this FIG. 3 , adjacent (First and Second) substations 100 and200 are shown to be 50 miles apart. Relay 50 monitors the currents inelectric power grid 51 on the specific transmission line associated withthis specific transmission line linked to Relay 50 at First Substation100. The power grid 51 transmission system is a three-phase system totransport power over long distances to safely and economically deliverenergy to meet customer demand. The power grid 51 illustrated in thisFigure is a three-phase alternating current system represented bytransmission line conductors 52, 54, and 56. Relay 50 monitors or sensesthe current and voltage levels in each of the phases of the three-phasesystem. A circuit breaker 86 is provided for disconnecting thetransmission line being protected from the power grid 51 when aconductor (wire) fails for any reason, such as a broken conductor(wire), a failed splice, gunshot damage, failed connectors or othercomponents resulting in an open conductor condition.

Relay 50 receives input voltages from A, B, C phase potentialtransformers 58, 60, and 62 on transmission line conductors 52, 54, and56, and the proportional values are connected to Relay 50 by wires 70,72 and 74 to provide proportional voltage values to Relay 50 connectionsat VA, VB and VC, respectively.

Current levels on the transmission line conductors 52, 54, and 56 areperformed by connecting a current transformer or some type of couplingcapacitor voltage transformer, or other current sensing device to theline conductors 52, 54 and 56 at A, B, C phase current transformers 64,66 and 68. The current flow output of A, B, C phase current transformers64, 66 and 68 are directly proportional to the line currents in lineconductors 52, 54 and 56. These current transformers 64, 66 and 68 arephysically connected or magnetically coupled to each line as shown inthe Figure. The primary windings of transformers 64, 66, and 68 areenergized in accordance with the line currents in line conductors 52,54, and 56, respectively. The secondary windings of the transformers 64,66 and 68 are connected to Relay 50 via lines 76, 78 and 80,respectively at IA, IB and IC. Relay 50 is connected to the circuitbreaker 86 via wire 84 connection at Relay 50 and terminating at theassociated circuit breaker. This is commonly known as output contacts toperform the trip function located in the circuit breaker controlcabinet. Wire 82 connects relay 50 to ground GND, as shown.

There is a second present invention Relay 94 at substation 200 withcircuit breaker 88, that is 50 miles downstream from substation 100.Relay 94 is identical to Relay 50 and therefore its details are notrepeated.

Relay 50 includes a communications port 90, such as a RS-485 serialport, or RS-232 or Fiber Optic connection which is used to transfer datato/from a remote location communications center 96 and as a direct linkbetween Relay 50 at substation 100 of a transmission line, and, Relay 94at the next substation 200 at the other end of the transmission line tocommunicate the status of the line from both ends. Relay 50 alsoincludes a second communications port 92, such as a USB port which isprovided for testing and local programming of Relay 50.

The relays 50 and 94 are coordinated by their programming andcommunications center 96. In these preferred embodiments, at a minimumeach relay would monitor three lines for capacitive potential orcapacitive current to recognize deviations from preset (programmed)acceptable operating ranges. More preferably, they each monitor threelines for a) instantaneous undercurrent, in combination with b) linedifferential overcurrent, and/or c) instantaneous undercurrent, incombination with d) negative sequence overcurrent, to recognizedeviations from preset (programmed) acceptable operating ranges. In somepreferred embodiments, the current magnitudes and phase angles arecompared. Degree of phase synchronization may be determinative orcontribute to the analysis to determine whether a significant enoughdeviation has occurred to trigger tripping breakers.

FIGS. 4 and 5 show high voltage transmission lines before a break andafter a break (before shorting), respectively, with present inventionrelays (PIRs) at each substation. Both Figures are taken together inthis discussion and identical components are identically numbered. Apower generating station 201 generates three phase electricitytransmitted by lines 203, 205 and 207 to step-up substation 209.Substation 209 has a present invention relay PIR 241 that functions inlike fashion to relay 50 of FIG. 3 . The power is transmitted at highvoltage over the three phase lines from tower 211 to subsequent towers213, 219, 221, 223 and 225. There are large industrial consumers thatdraw from these lines such as factories 215 and 239. There aresubstations along the way, including substations 217, 227 and 237 andeach has a Present Invention Relay 243, 245 and 247 respectively, suchas described above in conjunction with relay 50 of FIG. 3 . Thesubstations are step-down substations (with a step-down transformer toreduce voltage) that distribute power to users via conventional poles231 and 233 to users such as school 229 and residence 235. Because thePIRs monitor upstream and downstream, when a line breaks (as shown inFIG. 5 between towers 219 and 221) the nearest upstream and downstreamPIRs (243 and 245) monitoring the aforesaid conditions, will see deviantconditions generated from both ends of the break, and will direct abreaker tripping associated with those two substations (217 and 227) forthe broken line before the broken line segments (ends) touch a tower orground or other short. This happens in less than 25 milliseconds andcompletely prevents any short or ground from occurring and eliminatesany collateral damage or worse-catastrophic damage to person, structure,animal, flora and fauna.

FIGS. 6, 7, 8 and 9 show various present invention AND gate/OR gatearrangements used to monitor conditions and initiate breaker tripping toprevent ground faults after a line break and before a line touches atower, pole or ground. Identical components shown in each of theseFigures are identically numbered.

In FIG. 6 , gate diagram 310, the preferred AND gate 307 and AND gate309 are used to require a tripping signal directive 303 through OR gate305. At AND gate 307, simultaneous deviations from preset ranges forline differential, block 315 and for undercurrent, block 317, arenecessary for an action signal to pass through the gate. At AND gate309, simultaneous deviations from preset ranges for directionalovercurrent T-1, block 319 and for directional current T-2 317, block321, are necessary for an action signal to pass through the gate. Oncean action signal passes through one AND gate or the other AND gate, ORgate 305 sends the trip output directive 303 to trip the breakers.

In FIG. 7 , gate diagram 320, components shown in FIG. 6 are identicallynumbered here, except that there is a different AND gate 311. This ANDgate 311 illustrates a preferred embodiment of the present invention.Here at AND gate 311, simultaneous deviations from preset ranges for adirectional overcurrent, block 323, and a negative sequence (current),block 325, are both required for an action signal to pass through ANDgate 311.

In FIG. 8 , gate diagram 330, all that is shown in FIG. 6 is repeatedand works the same way as in FIG. 6 , except that there is a third ANDgate 313. Here at AND gate 313, simultaneous deviations from presetranges for a negative sequence (voltage or current, preferably current),block 327, and an undercurrent, block 329, are both required for anaction signal to pass through AND gate 313.

In FIG. 9 , gate diagram 340, all that is shown in FIG. 6 is repeatedand works the same way as in FIG. 6 , except that there are now four ANDgates, namely, AND gates 307, 309, 311 and 313 each functioning as setforth above in FIGS. 6, 7 and 8 .

While these gates assure reliability of the system by buildingredundancy into it, other variations for gate requirements within thevarious conditions monitored in the present invention may bealternatively be used without exceeding the scope of the presentinvention.

Examples 1 and 2 Prior Art vs Present Invention Protection Systems—500Kilovolts Transmission System

FIGS. 10 and 11 , respectively, illustrate Prior Art protection systemsand Present Invention protection systems analysis for an actual 500kilovolt, 1500 amp high voltage transmission line, and the significantability of the present invention system to completely eliminatecollateral and catastrophic damage that is possible or even likely tooccur with the Prior Art systems.

In FIG. 10 , Example 1, the prior art system of shutting down powerafter a fault is identified, is shown in graphic format as current vs.time. (Note that as to all FIGS. 10 through 13 , the horizontal timesegments and the vertical voltage segments are not intended to beproportional, only illustrative. The values in amps are accurate basedon real conditions and calculations.) During t-1, the system is runningwith no breaks and hence has a normal average current of 1650 amps. Attime t-2, a line breaks and current drops to approximately 100 amps.This is when the broken line is falling but has not yet hit or touched aground or short object, such as a tower or other structure or earth.This amperage stays at 100 until ground occurs at t-3, and then thecurrent leaps to 3514 amps. This is enough to cause fires, destroybuildings and kill people, fauna and flora. At t-4, the breaker istripped and current drops to 0, but it is too late as damage such aswildfires, has already occurred.

In FIG. 11 , Example 2, the present invention system of shutting downpower before a fault occurs, is shown in graphic format as current vs.time. During t-1, the system is running with no breaks and hence has anormal average current of 1650 amps. At time t-2, a line breaks andcurrent drops to approximately 100 amps. This is when the broken line isfalling but has not yet hit or touched a ground or short object, such asa tower or other structure or earth. This amperage stays at 100 untilthe present invention recognizes micro condition changes and trips thebreakers, typically within 20 to 30 milliseconds, and thus, no groundoccurs at t-3. The current remains at 0 amps. Because no fault or shortoccurs, all possibility to cause fires, destroy buildings and killpeople, fauna and flora, are mitigated or eliminated. At t-4, thebreaker has already been tripped and current remains at 0, until repairand restoration are completed, and then, the transmission is back tonormal.

Examples 3 and 4 Prior Art Vs Present Invention Protection Systems—115Kilovolts Transmission System

FIGS. 12 and 13 , respectively, illustrate Prior Art protection systemsand Present Invention protection systems analysis for an actual 115kilovolt, 100 amp high voltage transmission line, and the phenomenalability of the present invention system to completely eliminatecollateral and catastrophic damage that is possible to occur with thePrior Art systems. In these examples, FIGS. 12 and 13 are compared: Attime t-1, the system is running normal and the current is 503 amps, whenat time t-2, a line break occurs, the current in the broken line dropsto about 0.8 amps. This is when the broken line is falling but has notyet hit or touched a ground or short object, such as a tower or otherstructure or earth. This amperage stays at 0.8 and in the prior artExample 3, FIG. 12 , when the short or fault occurs, the current jumpsto 7000 amps with potentially catastrophic consequences. In the presentinvention Example 4, still in the time frame of t-2, the presentinvention recognizes micro condition changes and trips the breakers,typically within 20 to 30 milliseconds, and thus, no ground occurs att-3. The current remains at 0 amps. Because no fault or short occurs,all possibility to cause fires, destroy buildings and kill people, faunaand flora, are mitigated or eliminated. At t-4, the breaker has alreadybeen tripped and current remains at 0, until repair and restoration arecompleted, and then, the transmission is back to normal.

Although particular embodiments of the invention have been described indetail herein with reference to the accompanying drawings, it is to beunderstood that the invention is not limited to those particularembodiments, and that various changes and modifications may be affectedtherein by one skilled in the art without departing from the scope orspirit of the invention as defined in the appended claims. For example,the shapes of the various components herein may be changed; specificrelays may be modified or enhanced; communications may be by radio orfiber optics or by any rapid communication system that is or becomesavailable.

What is claimed is:
 1. A method for preventing ground fault or othershort circuit in a three-phase electric transmission line system havingat least three lines, caused by a break in a line, which comprises: A.providing a programmable relay protection system, including a pluralityof relay devices on each line of said electric transmission line system,said programmable relay protection system being programmed to include:a) preset parameter ranges of at least two high sensitivity electricoperating conditions, said preset ranges being acceptable operatingparameter ranges, one of said high sensitivity electric operatingconditions being instantaneous undercurrent, and one other of said highsensitivity electric operating conditions being selected from the groupconsisting of a) line differential overcurrent; b) negative sequenceovercurrent and c) combinations thereof; b) said plurality of relaydevices for said at least two high sensitivity electric operatingconditions being programmed to monitor each line; c) permitting closedcircuit operation when all of said lines show said at least two highsensitivity electric operating conditions are within said presetacceptable operating parameter ranges; d) tripping a plurality ofcircuit breakers on an open conductor broken line when that line showssaid at least two high sensitivity electric operating conditions areoutside said preset acceptable operating parameter ranges; and e)completing the following steps B. and C. within 1.0 second; B. sensingsaid open conductor broken line changes when said at least two highsensitivity electric operating conditions fall outside of said presetacceptable operating parameter ranges; and C. when said programmablerelay protection system senses said open conductor broken line when saidat least two high sensitivity electric operating conditions fall outsideof said preset acceptable operating parameter ranges, communicating toopen the plurality of circuit breakers on said open conductor brokenline, thereby shutting down power to said open conductor broken linebefore it otherwise causes the ground fault or other short circuit. 2.The method for preventing ground fault or other short circuit in athree-phase electric transmission line system of claim 1 wherein saidplurality of relay devices on each line is programmed to monitor bothupstream and downstream from each of said plurality of relay devicessuch that when the line is broken, the monitored high sensitivityelectric operating conditions of both ends of the break in the line arerecognized and reported in the programmable relay protection system toeffect said shutting down power to said open conductor broken line bytripping two circuit breakers, one being upstream from the break in theline and the other being downstream from the break in the line.
 3. Themethod for preventing ground fault or other short circuit in athree-phase electric transmission line system of claim 1 wherein saidprogrammable relay protection system, including said plurality of relaydevices are programmed to monitor said instantaneous undercurrent, andto monitor said line differential overcurrents to detect a currentimbalance on line-charging capacitive current.
 4. The method forpreventing ground fault or other short circuit in a three-phase electrictransmission line system of claim 1 wherein said programmable relayprotection system, including said plurality of relay devices areprogrammed to monitor said instantaneous undercurrent, and to monitorsaid negative sequence overcurrent.
 5. The method for preventing groundfault or other short circuit in a three-phase electric transmission linesystem of claim 4 wherein step C. shutting down the power to said openconductor broken line is delayed by a preset time within the range ofabout 0.3 seconds to about 1 second to protect against a false shutdown.
 6. The method for preventing ground fault or other short circuitin a three-phase electric transmission line system of claim 1 whereinsaid plurality of relay devices are programmed to be highly sensitive soas to monitor and measure said line differential overcurrent in therange of 0.01 to 0.1 amp.
 7. The method for preventing ground fault orother short circuit in a three-phase electric transmission line systemof claim 1 wherein said plurality of relay devices are programmed to behighly sensitive so as to monitor and measure said negative sequenceovercurrent in the range of 0.01 to 1 amp.
 8. The method for preventingground fault or other short circuit in a three-phase electrictransmission line system of claim 1 wherein said plurality of relaydevices are programmed to be highly sensitive so as to monitor andmeasure said instantaneous undercurrent in the range of 0.1 to 2 amps.9. The method for preventing ground fault or other short circuit in athree-phase electric transmission line system of claim 1 wherein saidplurality of relay devices are programmed to be highly sensitive so asto monitor and measure said line differential overcurrent in the rangeof 0.01 to 0.5 amp, and so as to monitor and measure said instantaneousundercurrent in the range of 0.1 to 1 amp.
 10. The method for preventingground fault or other short circuit in a three-phase electrictransmission line system of claim 1 wherein said plurality of relaydevices are programmed to be highly sensitive so as to monitor andmeasure said negative sequence overcurrent in the range of 0.01 to 0.5amp, and so as to monitor and measure said instantaneous undercurrent inthe range of 0.1 to 1 amp.
 11. The method for preventing ground fault orother short circuit in a three-phase electric transmission line systemof claim 10 wherein there are at least two AND gates and at least one ORgate for processing monitored data readings and tripping said pluralityof breakers, including a first AND gate that receives line differentialovercurrent readings and instantaneous undercurrent readings, andincludes a second AND gate that receives negative sequence overcurrentreadings and second instantaneous undercurrent readings.
 12. The methodfor preventing ground fault or other short circuit in a three-phaseelectric transmission line system of claim 1 wherein said programmablerelay protection system includes software and hardware for recognizingbreakage capacitive current within 10 milliseconds when said at leastone high sensitivity electric operating condition falls outside of saidpreset acceptable operating parameter ranges, and communicating to openthe plurality of circuit breakers on said open conductor broken linewithin 10 milliseconds, thereby shutting down power to said openconductor broken line before it otherwise causes the ground fault orother short circuit.
 13. The method for preventing ground fault or othershort circuit in a three-phase electric transmission line system ofclaim 1 wherein said programmable relay protection system includes theplurality of relay devices having phasors for monitoring all three phasevoltages and currents and phase angle similarities and differences todetect capacitive current and deviations from preset ranges thereof.